Fuse-plug



' F. H. KAISER.

FUSE PLUG.

APPLICATION FILED MAR. 26, 1918.

1,357,169, Patent ed 001;. 26,1920.

2 SHEETS-SHEETL {f7 F%Ck" I awe-n1 F. H. KAISER.

FUSE PLUG. APPLICATION FILED MAR. 26, 1918.

Patented Oct. 26,1920.

2 SHEETS-SHEET 2- uNiTs-n STATES PATENT orricn FRANK HENRY KAISER, 0F BUFFALO, NEWYORK, ASSIGNOR 'ro oAnoL G. KAISER, 0F BUFFALO, NEW YORK.

- FUSE-PLUG. r

Application filed March 26, 1918-. Serial No. 224,814.

To all whom it may concern: i

Be it known that I, FRANK H. KArsER, a citizen of the United States, residing at Buffalo, in the county. of Erie and State of New York, have invented certain new and useful Improvements in Fuse-Plugs, of which the following is a specification.

This invention relates to electrical fuse plugs. y

It is one object of the present invention. to

provide a fuse plug all of the parts of which may be assembled without the employment of solder and the parts of which may be furthermore readily and conveniently disassembled for the purpose of renewing the fuse wire. 7 g 1 Another object of the invention is to provide a fuse plug in which the electrical connections are of such nature that proper Contact will be insured between contacting parts without the employment of solder to form such a contact or union.

Another object of the invention is to so construct the plug as to permit of the ready assembling of the fuse wire therewith and the securing of the ends of the wire withoutany likelihood of distorting the wire. breaking the wire, or cutting intov the same, which would be likely to impair its conductivity. I a

As a further object the invention is de-' signed to provide a fuse plugsoconstructed that there will be no likelihood of fire being caused when the plug is blown, means being provided for permitting of the escape of the gases and heated air resulting from'the fusing of the wire without at the same time permitting of the escape of flame from the interior of the plug. p

A further object of the invention is to provide a fuse plug with means adapted to automatically indicate when the plug has been blown so that a blown plug may be readily detected even among many others of its kind without the necessity of testing each plug.

7 Another feature of the invention resides in the prov'isionof means for preventing the assemblage within the plug of a fuse wire of a larger diameter than that which 1s su1t-' able for the voltage or amperage'indicated. The invention has as a furtherobwct to Specification of Letters latent. Patented Oct. 26,1920.

provide a fuse plug the" parts of which may be readily and quickly assembled and later dlsassembled when it becomes necessary to renew'the fuse wire'an'd the indicating means, andin this connection the invention further has as its object'to so con-" struct the body of the plug as to provide means for guiding the fuse wire into as it is inserted into the plug.

In the accompanying drawings:

' Figure l-is a vertical longitudinal sectional view through a fuse plug constructed n accordance with-the principles of the present invention; I 7

Fig. 2 is a similar view taken me plane substantially at right anglesto the plane of Fig. 1; p e v Fig. 3 is a top plan View of the plug assembled as shown in F ig; 1;

Fig. i is a horizontal sectional view on the line 44 of Fig. 1;

Fig. 5 is a View similar to Fig. 3 but with the cap of the plug removed;

F ig. 6 is a perspective view of the attaching member for oneend of the fuse Wire;

Fig. 7 is a perspective view of the indicator tape; 7

Fig. 8 is a vertical longitudinal sectional View through a modified form of plug body;

Fig. 9 is a horizontal sectional view onthe line 9'-9- of Fig. 8 i

Fig. 10 is a view similar to Fig. 8illustrating a further modification of the invention.

is indicated in general by the numeral 1 and the said body is as usual constructed of porcelain or similar non-conducting ma venient grip portion whereby the plug may be turned into and out of its socket'and Without the necessity of touching any of the place In the drawings, the body of the fuse plugmetal parts of the plugs. The body 1 is of the hollow formation, shown in the several figures of the drawings, so as to house the fuse wire and the cavity of the body is indicated by the numeral 3, the said body be- 7 ing open at one end and closed at the other,

as'indi'cated by the numeral 4L Interiorly the body has its wall increased in thickness,

as 'indicated by'the numeral 5, this thickened portioni extending longitudinally of the body from the closed end a thereof "toxa point adjacent the open end of the body and providing within the said body a longitudinally extending flat face (3. The bodyispreferably interiorly gradually increased in diameter from its closed end toitsopen end so asto permitof the ready introduction of a metallic disk 7 whichis designed to. seat. withinthe closed end 4 of the body;

in the'mannerclearly shown in Figs, 1, 2

and 4; of the drawings. This disk 7 is circular exceptthatat one side it is cutchordally, V {as indicatedbylthe numeral 8, so as to pro vide a straight edge or side designed to engage against theface 6 of the thickened portion 5 of the'wall of the body whereby to prevent rotation of the disk 7 withinwthe closedend of the body. Centrally the said disk is formed with an opening 9 the wall v of which is threaded to receivethe threaded shank of a binding screw 10 which shank is inserted through an opening 11 formed 1n the closed end- 1 of the body. The screw 10 is provided with flat head 12 which is of relatively large diameter and which. is preferably provided with theusual diametric manner above stated and that, therefore,

the screw may be adjusted from the exterior of the plug and without the necessity of inj troducing through the open end of the plug an implement for holding the said disk 7 against rot ation. Near its periphery the disk? 1sformed w th another opening, in-

dicated. by the numeral 14, and this opening registers with the inner end of an opening 15 which is formedthrough the closed end l of the plug body, the opening 15 being flared: at its. outer end as indicated by the numeral 16, and rounded so that no sharp corners will be presented to the fuse wire msertedthrough this opening. he clearly shown inFig; 2 of the drawings, one end .ofthefuse wire which is indicated by the -numeral 17 ,is fitted through the openings 2 14: and15 and its portion which extends e2;-

.t eriorly of the closed end of the plug body is looped above the, shank of the binding screw 10 and the screw is then tightened until its; head 7 1,2 firmly binds the looped end of the fuse wire against the closed end 4 of the said body. Also by reference to Fig. 2 it will be understood that having anchored: this. end of the fuse wire, even should a sharp or strong pull be exerted 7 its other end and then drawn taut through heat'orblister when acurrent of high value is passing through the plug. The disk? serves as a nut for the binding screw 10, and said disk serves also as a means for preventing the assemblage within the plug of a fusewire of .a diameter greater than that suitable for the maximum current which the plug is to. carry. In. order that the disk7 may serve this purpose, the opening 14 therein will be formed of such diameter as to permit of the passage therethrough of a fuse wire of a certain specified maximum diameter. Thus if the plug is designed to carrya current of a certain value, one of the disks 7 will be assembled with thebody of the plug having its opening 14 of a diameter to receive the, largest diameter of fuse wire suitable for carrying a current of such value and therefore with the disk in place, a fuse wire of a larger diameter can not be assembled withthe plug.

In order to accommodate the member which is provided for anchoring the other end of the fuse wire 17, thewall of the body 1 is. formedwith a longitudinally extending passage 18 in its thickened portion 2, the

passage opening at one end at the upper end of the saidthickened portion 2 and at its other end into a longitudinally extending groove 19 formed in the outer side of the L plug body l below the portion 2. Exteriorly the body 1 is formed with several screw threads 20 immediately below the enlargement 2, which threads are designed to be engaged by the threads 21 of a shell 22 designed to be fitted onto the lower portion of the plug body. As there are only two or three of the threads 20 present, the said shell 22 may be readily and quickly assembled with the plug body by slipping it onto the said lower portionof the body for substantially its entire length and then turning it into engagement with the threads 20. This shell is, of course, designedto thread into the socket for the plug and to make electrical contact with the lining of the socket, and the. lower orouter end of, the

shell, of course, terminates short of the closed end of the plug body, as indicated by the numeral 23, so as to be suitably spaced out of contact with the head 12 of the screw 10. The anchoring member above referred to is indicated in general by the numeral 24 and the same is formed of a suitable conducting metal and comprises a shank 25 which is fitted through the open end of the plug body and into the passage 18' with'its end portionextending into thegroove 19. i The said end portionoi the shank 25 is suitably crimped so as to match with the threads 20 upon the exterior of the body'l and, consequently, when the shell 22 is threaded into place, the end portion of the shank25 will have good'electrical contact with the shell and such contact is therefore secured without the necessity of soldering the member 25 to the said shell. At its upper end, or in other words, that end'located next adjacent the open end of the body 1, the shank 25 is bent to extend inwardly at right angles" toward the longitudinal axis of the body, as indicated by the numeral27, and the portion 27 terminates in a flat horizontally disposed head 28 formed at its periphery with one or more pairs of spaced fingers 29, and centrally with an opening 30 thewall of which is screw threaded. In the form of this member, illustrated in Fig. 6 of the drawings, the head 28 is provided with three pairs of the fingers 29 which extend generally in a radial direction from the head and after the fuse wire 17 has been led into the interior of the body 1 of the plug, it is to be engaged within the notch formed between any one of the pairs of fingers 29 and then looped about the shank 31 of a binding screw 32 threaded adjustably into the opening 30. By leading the fuse wire through the notch formed between a pair of the fingers 29, the wire is held against being twisted or otherwise dis torted or mutilated when the binding screw 32 is tightened to secure the looped end of the wire. By reference to Fig.' 1 of the" drawings it will be observed that the portion 27 of the anchoring member lies directly flat against the upper end of the thickened portion 50f the wall of the plug body 1 so that the end of this'portionconsti tutes astop shoulder to limit the movement of the anchoring member in the direction in which it is inserted into the plug body, or in other words, in'the direction of the binding screw 10 so that the fuse wire may be drawn as taut as desired without likelihood of displacing the anchoring member 24. In order to secure the shell 22 in place after it has been threaded onto the lower portion of the plug body, a recess 33 is formed in the outer surface of the said portion of the body immediately below the enlargement 2 and preferably .oppositethe groove 19 and the wall of the shell 22 is to be struck in so as to scribed.

seat within the said recess for the purpose stated.

As before stated, meansis provided for automatically giving visible signal when the fusefis blown so that a blown fuse, may be instantlyjrecog'nized among a number of intact fuses therebyobviating the necessity of testing or' inspectingagreat number'of fuses before locating the one which is to be renewed, and this means will now 'be deof a metallic cap 32 which, for a purpose to be presently explained, is provided centrally with an opening 35,'the wall of the I Generally speaking, the open end i of the fuse plug body 1 is closed'by means cap being screw threaded as indicated by V the'numeral-36 so as to adapt thelcap to be removably fitted onto the upper endportion of the said body, or in other words, that portion which extends beyond the upper side of the enlargement 2. A relatively thick and stout disk of asbestos or other suitable material indicated by the numeral 37, is disposed against the upper'or open end of the body 1 and,when the cap 34 is in place, is housed within the said cap.

This disk 37 completely closes the said open end of the plug body, and m'ountedupon the outer faceof the said disk is a shell or cap 38 having a filling 39 of an explosive powder such for example asgun powder. A fine wire 40 is fitted at one end through the disk 37 with its said end extending into the filling 39 and the other end of this wire is'coiled or wrapped' as at 41 about thefuse wire at a point approximately midway between the ends thereof. A thin disk 42 is disposed within ,the closed end of the cap and closestheopening 35 and thisdisk is preferably formed of asbestos although any other suitable 1 material may be employed, the materialoit the disk being capaa ble, however, of'being more or less readily torn fora purpose which will be presently explained. T he numeral 43'indicates a strip of asbestos or other suitable 'inaterial which is preferably colored red and is secured at one-end in any suitable manner-as indicated by the numeral 44 tothe outer face of tlie disk 37, the free end of this strip extending over the cap 38 and between the said cap and the disk 42 at a point directly opposite the opening 35 in the cap 34. As con cerns this feature of the invention it will be understood that prior, to actualpfusing of the fuse wire 17, the wire will becouieheated. Due to the fineness of the wire 40, this wire wi l be heated to redness due to the heat from thefuse wire and, therefore, the powder within the cap will be ignited and the fillingwill explode causing the end Y ibdtebe g v fiic e tin tsepe o nevertheless it will be understood that varione oth r means may ei mployed o imithebodyof the plug,in that form of the V invention shown in Figs. 1 and 2 ofthe drawings, is formed withvent passages of'which there maybe any, desired number and which passages preferably are. curved radially, and downwardly so as to discharge through the under, face of the enlargement.

In other words, the passages are curved from the inner surface'of the wall of the plug body toward that end of the plug at which the contact 12 islocated,

In that form of the invention shown in b Fig. 1 'ofthe drawings, the plug is formed in its wall with passages 46 which extend longitudinally of the, wall and which open at onev end through the inner face of, the

wall near; the closed end 4 of: the plug and at; the other end through the rear face of theenlargement 2, as indicated by the numeral 47, the passages adjacent their lastmentioned ends being curved outwardly and thence rearwardly as indicated by the numeral 48. Small branch passages 49 also open through the inner surface of thewall of the plug and, communicate at intervals 7 with the respective passages 46.

In that form of the invention shown in Figs. 8 and 9 of the drawings,the wall of the plug body is formed interiorly with a tubular guide 50 for the fuse wire, the bore of this guide, indicated by the numeral 51,

having one end located opposite and close to theopening- 15 and its other end terminating slightly short of the upper or outer.

end of the thickened portion 5'of thev wall of the plug. The bore 51, of course, serves as a guide for the fuse wire and thus perimits: of more ready assemblage of the wire with the plug body and the anchoring device provided thereon.

It will be understood that the disks 37 and 42 being of asbestos or similar material, are of insulating character and are also fireproof. Therefore there is no likelihood of current being transmitted to the cap 34:, nor is there likelihood of; flame being discharged through the open end of the plug body from the are produced at the time of fusing of' the wire1 7; It will" be observed that the vent passages in the, wall of the plug are tortuous, or in other words, do not open along straight lines through the said wall so that thereis gradual expansion of the gases and heated wh n he fuset lhlown. and epesseg f me hrought pa s gesis fec ually prev ed; 1' Ha ng-th de c be he n en e hat is claimed, as new is:

A us p e ud na b dy hav n a use wi epas g op etbo h nds. and: ex.-

tending, longitudinally in the Wall of the edy, n lspa e e nsy r ed y he ody for securing the endsof the fusewire, V V 2. In afuseplug, a body for housing -the e W re, andmeans o e u ng n) e d; Qf

a j n'g e en diu tably hre dedth ou 'thewireineluding a member within the, plug 7 having severaL pairs of fingers between any heQneninand; erv ng l t pa r of I fingers.

3, Ina fuse plug, a body having a closed e d; pro ided; ta p ng r th pa sage Qf a, fuse ,wir a disk removably fitted within theclosed endof the body and havns; u e r gearin penin m d therein through which the fuse wire is to be passed d a nding: ment for h n of the fuse wire fittedthrough the closed end of: the. body and securing, the said disk in place. V

4; na l se pl s, a o y a ng c s end. provided with an opening: for the passage Of5t-1'1Q f1l$e wire, a disk removably fitted within, the closed; end; of the body, means within the body coacting with the disk to prevent. rotation thereof, the said disk being formed with anopening designed to register with the first-mentionedopening and constituting means; for preventing the insertion into the body of the plugiof awire of a diameter. greater than a predetermined maximum] diameter, and means for securing the isk n p ace n bindl s h end of the wire; I

5. In a fuse plug, a hollow body having closed end: provided with an opening for the passage of; a fuse wire, the bodyinteriorly' having-its wallprovide'd with a flat-' tenedportion, a disk removably fitted into the closed end of the. body and havingaa straight side designed toengage the said flattened portion of the wall; of the. body, the said disk being formedwith an opening for the: passage of the. fuse wire designed .to prevent: the insertionof a fuse wire of a diameter greater than a predeterminedmaximum diameter, and a binding screw fitted through the closed end of the body and threaded intothe'said diskand securingthe end of the fuse wire and also securing the diskin place. i t

6. In a fuse pluga body forhousing the fuse wire, a, metallic contact shell fitted to he b dy, he bo yha a. Pas a iehinaemanation etween; ts nterio and exterior, and means for securing an end of the fuse Wire including a member having a shank disposed within the passage and contacted by the said shell, the shank at the inner end of the passage extending inwardly toward the center of the body and being provided with a plurality of pairs of spaced fingers between which the fuse wire near its end may be disposed and held, the said shank adjacent the inner ends of the fingers being 10 provided with an opening, and a binding screw fitted into the opening for binding the end of the fuse wire.

In testimony whereof I affix my signature.

FRANK HENRY KAISER. [11. s] 

